This study is an experimental introduction of web-based lecture delivery into a majors-level introductory biology course. Web-based delivery, achieved through the use of prerecorded Voice-Over PowerPoint video lectures, was introduced on a limited basis to an experimental section while a control group, with the same instructor, received standard in-class lecture delivery. Select lectures were delivered to the experimental section via videos, replacing in-class attendance of live lectures. Through the course of the semester, a detailed analysis reveals that internet-delivered video lectures prepared students for exams as effectively as live in-class lectures. This indicates that students can learn complicated biology course material through prerecorded, web-delivered lectures much as they do through in-class attendance of those same lectures. Although further careful study is needed, these results warrant further experimentation in web-based teaching methods in the sciences. (Contains 1 table and 7 figures.)